Central Hair Drying System

ABSTRACT

A central system for delivery of an airflow at a variety of temperatures and rates to individual dryers, replacing the individual motor, fan and heating elements in the dryer. The system may produce a heated airflow based on multiple user-input temperature and airflow level commands. Multiple dryer users can independently control their desired temperature and the airflow level. The system may utilize an HVAC air delivery system and comprises a central control system with preprogrammed algorithm to operate the HVAC to achieve the desired results. A number of sensors can provide inputs to the control system.

FIELD OF THE INVENTION

The present teachings generally relate to a central system fordelivering independently controlled temperature and airflow rate to aplurality of individual dryers and thus providing a reduced-weight andlow-noise dryer.

BACKGROUND OF THE INVENTION

A variety of hot air blowing devices are known for the drying of humanand animal body parts and, in particular, drying, dehumidifying, shapingand styling of hair. The hair dryer is usually hand held and portable.Such devices, whether portable or not, commonly contain a housing whichcontains a powerful electric motor, a fan, heating elements, controlfeatures and a conduit to deliver directional heated or non-heatedairflow.

The conventional hair dryer poses several health hazards to theprofessional users and their clients. The conventional hand-held hairdryer device is relatively heavy and hence challenging to maneuver,which consequently poses an ergonomic hazard for a professional user,for example hairdressers, groomers and beauticians. Repetitivemanipulation of a heavy dryer is one of the causes to prevalence ofoccupational diseases associated with neck, shoulder, wrist and handailments among the professional users, as documented by European Agencyfor Safety and Health at Work.

Another occupational hazard of a conventional hand-held hair dryer isthe noise emission generated by the motor and the fan, typically in therange of 70 dB to 90 dB. This level of noise is classified as “veryloud” and processes which emit noise exceeding 80 dB to 85 dB causeirreversible hearing damage, as determined by the AmericanSpeech-Language Hearing Association. During simultaneous operation ofseveral dryers, the noise level increases considerably. Long-termexposure of professionals and clients to the noise is undesirable.Another negative aspect of the high noise level is the general acousticpollution which impedes in-person and phone communication between theprofessional users and the clients. Utilization of the conventional hairdryer poses hygienic risk which stems from the fact the air drawn intothe dyer and then directed toward a client, is a recirculated indoorair. When a conventional dryers are operated in a professional facilitywith multiple clients, there is a high risk of transporting contaminatedair that may expose clients to other clients' germs, bacteria,microorganisms, fungi, skin particles and dust.

Several other negative aspects of the conventional dryer exist due tothe fact that every dryer contains heating elements and a powerfulelectrical motor. A conventional dryer has to be frequently replaced dueto a reduction in performance and has a typical short lifespan of onlyabout 200 to 300 hours, which substantially increases the operationalcosts of the facility. In a typical commercial facility operating dryersthe heat generated by the individual motors of the dryers significantlyaffects the ambient temperature. Typical 2000W dryer which operates fivehours per day, has a relatively large carbon footprint of about 1500 kgof CO₂ released per year.

What is needed is a long lifespan, reduced weight and low noise dryerthat delivers non-contaminated airflow at the lower cost. The objects ofthe invention is to overcome some or all of the above drawbacks in theart. It is one object of the invention to provide a reduced weight,lower noise and hence more ergonomical dryer by eliminating the need tohave a motor/fan/heating system within individual dryer. This purpose isachieved by utilizing a central air delivery system, such as HVAC (Heat,Ventilation and Air Conditioning) where the motor/fan/heating elementsare located remotely relative to the dryer. Another object of thisinvention is lowering operational cost of a facility caused by a need offrequent replacement of multiple individual dryers and at the same timedeliver fresh air to each dryer by adaptation of HVAC central system todeliver outdoor air to plurality of dryer units. Another object of theinvention is to provide an improved combination in which desired airflowrate and temperature required by an individual user may be independentlycontrolled by the user.

SUMMARY OF THE INVENTION

One possible embodiment of the present invention includes a systemcomprising a first duct configured to conduct a first airflow that is ata first temperature and a second duct configured to conduct a secondairflow that is at a second temperature lower than the firsttemperature. The apparatus may further include first outlets that arespaced apart along the first duct, second outlets that are spaced apartalong the second duct and equal in number to first outlets. Theapparatus may further include dryer handpieces equal in number to thefirst outlets, Y-connectors, each Y-connector including a first conduitconnected to a respective one of the first outlets, a second conduitconnected to a respective one of the second outlets, and a third conduitconnected to a respective one of the dryer handpieces, for the connectorto combine a first portion of the first airflow with a second portion ofthe second airflow to yield a third airflow exiting the respectivehandpiece. The apparatus may further include first dampers, each firstdamper configured to control the first portion of the first airflow andsecond dampers, each second damper configured to control the secondportion of the second airflow. The apparatus may further include aprogrammable control system configured to control pressure of the firstairflow, control pressure of the second airflow, control the firsttemperature, and for each dryer handpiece, control the first damper andthe second damper that are associated with the respective dryerhandpiece to control temperature of the third airflow exiting at thedryer handpiece.

In another possible embodiment of the present invetion each first damperis located in a respective one of the first outlets, and each seconddamper is located in a respective one of the second outlets. The presentinvention may further include a first fan configured to generate thefirst airflow and controlled by the central control system and a secondfan configured to generate the second airflow and controlled by thecentral control system. The invention may further include temperaturesensors, each temperature sensor configured to measure temperature at arespective one of the air supply units, and wherein the control systemis configured to control temperature at the respective handpiece basedon the temperature measured for the respective one of the air supplyunits. The invention herein may also include pressure or airflowsensors, each pressure or airflow sensor configured to measure apressure or an airflow rate at a respective one of the air supply units,and wherein the control system is configured to control pressure atrespective air supply units based on a feedback signal from the pressureor the airflow sensors by controlling fan motor speed.

In another possible embodiment of the present invention, the system mayfurther include a preheater located upstream from the first and secondair supply units and configured preheat the first and second airflows tothe second temperature, and a first heater located downstream from thepreheater and configured to heat the first airflow to the firsttemperature. Wherein the central control system includes a controller,and for each dryer handpiece: a first motor, controlled by thecontroller and coupled to the corresponding first damper, to enable thecontroller to control the corresponding first damper; a second motor,controlled by the controller and coupled to the corresponding seconddamper, to enable the controller to control the corresponding seconddamper.

BRIEF DECRIPTION OF DRAWINGS

In the accompanying drawings which form part of the specification:

FIG. 1a and 1b is a schematic general view of a facility using thecentral hair drying system to supply air to a number of dryer units(dryer handpieces).

FIG. 2a illustrates a cross-sectional plan side view of one embodimentof the central air supply system with an ambient air supply unit and aheated air supply unit, and 2 b depicts a cross-sectional plan side viewof another embodiment of the central air supply system with atemperature compensation unit (a preheater), an ambient air supply unitand a heated air supply unit.

FIGS. 3a, 3b and 3c illustrate an enlarged schematic designconfigurations of paired motor-driven dampers shown in differentoperational positions.

FIGS. 4 a, b, c depict a schematic general view of differentconfigurations of an ambient air supply unit, a heated air supply unitand a Y-connector (a mixing chamber), a connection to the dryerhandpiece is also shown.

FIGS. 5a, 5b and 5c shows a chart of the connectivity between a dryerhandpiece, central control system and the paired dampers, including anoptional preheater.

Table 1 presents examples of an operational relation between thepositions of paired motor-driven dampers and the correspondingtemperature of airflow emerging from the dryer handpiece.

Table 2 presents examples of tabulated values of airflow (in units ofcfm) vs. fan speed.

Table 3 presents example of tabulated values of airflow (in units ofcfm) vs. fan speed dampers position for a system comprising four dryers.

Drawings are not drawn to scale for reasons of understanding.Corresponding reference numerals indicate corresponding parts throughoutthe several figures of the drawings.

DETAILED DESCRIPTION

The explanations and illustrations presented herein are intended toacquaint others skilled in the art with the invention, its principles,and its practical application. Those skilled in the art may adapt andapply the invention in its numerous forms, as may be best suited to therequirements of a particular use. Accordingly, the specific embodimentsof the present invention as set forth are not intended as beingexhaustive or limiting of the invention. Additionally, some well-knownstructures or functions may not be shown or described in detail, so asto avoid unnecessarily obscuring the relevant description of the variousembodiments. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled. The disclosures of allarticles and references, including patent applications and publications,are incorporated by reference for all purposes.

According to the present invention, an electrical motor, a fan andheating elements generating an airflow, are removed from theconventional dryer handpiece, and instead, a central system, installedin a central location, generates the heated or non-heated airflow anddelivers it to a plurality of dryers. The central and remotely locatedsystem supplies the necessary airflow rate with the required temperaturecontrol, hence considerably reducing the weight of the drying unit,which now may mostly comprise switches and air conduits. The heatedairflow is dispersed using a central airflow generating system andcentral heating elements, through an air ducting system and extendableflexible modular tubing, to the dryer. The required adjustments inairflow rate/pressure and in temperature are regulated by a centralcontrol system according to a preprogrammed algorithm and based onmultiple inputs, for example, from dryers and sensors.

As used herein, the terms “dryer”, “dryer unit”, “hair dryer”, “dryerhandpiece” and “hand-held dryer” are used interchangeably. The term “airsupply unit” and “duct” are used interchangeably. The term “dryer” doesnot require any particular geometry and/or configuration. The term“blower” or fan describe any mechanical device that can move air orgases, such an impeller or centrifugal fan that can achieve the requiredair pressure. The term “central control system” and “control system” areused interchangeably. The term Y-coupler, Y-connector and “mixingchamber” are used interchangeably. Various embodiments of the inventionwill now be described with reference to the figures.

Illustrative Embodiments

The following examples are provided to illustrate the invention, but arenot intended to limit the scope thereof. All parts and percentages areby weight unless otherwise indicated.

FIGS. 1a and 1b show an overall environment in which the invention maybe situated. The figure illustrates a central air supply unit 200 influid communication with dryers 120 via extendable and/or flexibletubing members 130. The central air supply unit 200 or its parts can beinstalled on close proximity to a room ceiling, a body of a wall or afloor, as shown in FIG. 1 a, or inside an additional structurepositioned in a remote and/or central location in relation to the roomwhere dryers are operated. The central air supply unit or parts of thecentral supply unit may be installed on a different floor, or in adifferent building, or outside the walls of the main building, as shownin FIG. 1 a. The central air supply unit may include structural supportelements (not shown). The central air supply unit may include a housing280. The central air supply unit may be substantially hidden from theroom view as shown in FIG. 1. Preferably, the central air supply unit isan adapted HVAC (Heating, Ventilating and Air Conditioning) system. Thecentral air supply unit comprises at least two air supply units. Thedifferent functions of the central air supply system are regulated by acentral control system, for example, the temperature and thepressure/rate of the airflow in air supply units. The central controlsystem is preprogrammed with an algorithm (logic control) that operatesthe HVAC system to achieve the desired results. In one preferredembodiment, there is one central control unit 270. The central airsupply unit or its housing may be painted, decorated and/or thermallyand/or acoustically partially insulated. The central air supply unit mayinclude acoustic absorbers or acoustic dampers, active or non-active.The configuration shown in the FIGS. 1a and 1b are only an example, theconfiguration of the entire central air delivery system is a designchoice. A facility may have more than one central unit wherein each mayhave a separate central control system.

One embodiment of the invention is depicted in FIG. 2 a. FIG. 2a shows across-sectional view of the central air supply unit 200. The central airsupply unit may include a housing 280. The housing 280 may includeacoustic insulation layer and/or a heat insulation layer. In oneembodiment, the central air supply unit 200 comprises at least twoseparate air supply units or ducts positioned adjacent to each other, anambient air supply unit 232 and a heated air supply unit 222. Theambient air supply unit may include an evaporator or a cooling system(not shown). The ambient air supply unit delivers air at the temperaturerange of about 15 C to 35 C, or about 18 C to 30 C, or about 22 C to 27C.

Referring to FIG. 2a and FIG. 2 b, a first air supply unit, a heated airsupply unit, 222 comprises an air inlet 201 and a second air supplyunit, an ambient air supply unit, 232 comprises an air inlet 202. Theair inlets are typically positioned in one or more terminal locations ofthe HVAC system and draw an outdoor (outside) air. The first air supplyunit 222 has a first air outlet 223, and the second air supply unit 232has a second air outlet 233, the first and the second air outlets isspaced apart from the corresponding variable speed fan systems.Preferably, the variable speed fan systems are installed outside abuilding. Preferably, first air outlets have a first motor-drivendampers and second air outlets have second motor-driven dampers. Theoutlets and the dampers are schematically shown in FIG. 2 a, 2 b and inmore detail in FIG. 3 and FIG. 4. In one embodiment, the first and thesecond dampers may be installed within the first and the second airoutlet openings. In another embodiment, the first and the second dampersmay be installed downstream from the first and the second air outletopenings, e.g the dampers may be spaced apart from the air outletopenings, as schematically shown in FIG. 4. First and second air inletscomprise an air filter element 203. The filter element generallycomprises common filter media such as fibrous web, and may furtherinclude functional filter layers. The filter element(s) are positionedin the air inlet such that there is a relatively small area is availablefor air to bypass the air filter elements. Preferably, substantially allair bypasses the air filter to ensure filtration of the entire airflow.The purpose of the filter is to limit the entry of airborne solidparticles, debris, dust, as well as preventing animals or insects frompassing through the filter. The filter elements may be replaceableand/or cleanable to ensure adequate airflow within a desired airflowrange.

The walls of the air supply units are generally continuous between theoutlets so as not to allow air to enter or leave the air supply unitother than at the inlet and the outlet respectively and form airflowconduit or passage. The air conduit may be a duct, a chamber, a pipe, atube or a hose. In one embodiment, the duct structure may besubstantially rigid, and comprise a sheet metal, a rigid heat resistantplastic or any substantially material that withstand the requiredpressure and heat. In another embodiment, the duct structure may beflexible as illustrated in FIGS. 4b and 4c and may comprise Aluminumlayer and thermally insulating layer. In another embodiment, the ductcomprises a combination of the substantially rigid and substantiallyflexible segments, as illustrated in FIGS. 4b and 4 c. As shown in FIG.4 b, the air outlets disposed in the rigid segment of the duct. As shownin FIG. 4, the rigid and the flexible ducts or their segments can be ofdifferent shapes, for example, round, rectangular, elliptical shape or acombination of the above. The air supply unit may be painted, decoratedand/or thermally and/or acoustically partially insulated. The air supplyunit may include acoustic absorbers and/or acoustic damping elements,active or non-active. The air supply units 222 and 232 may comprise anacoustic insulation layer, a heat insulation layer, a joint, a seam, aconnector, an adaptor, a fitting, a sealing, and rigid or flexiblestructural supports. Each of the air supply units 222 and 232 comprisesa variable speed fan system, the variable speed fan system locatedbetween the air inlet 201 and an air outlet 223 in the heated air supplyunit, and similarly, between the air inlet 202 and an air outlet 233 inthe ambient air supply unit. The air variable speed fan system comprisesa mounting support (not shown), a variable speed fan 240, 241, operatedby a variable speed motor 206, 207 and controls of the variable speedmotor (not shown), wherein the fan generates an airflow distributedthrough an airflow distribution system of air outlets and theircorresponding dampers. The central control system 270 may include acontroller. The controller is configured to communicate with thecontrols of the variable speed motor to regulate the speed of the fan,resulting in a change of the airflow rate. The motor may be operated ina continuously variable speed or discretely variable speed. A highpressure air zone is established within each air supply unit. Such aconstruction provides an airflow in the range of about 0 cfm to 450 cfm(cubic feet of circulating airflow per minute), or about 25 cfm to 400cfm, or about 75 cfm to 325 cfm. The typical air flow velocity is in therange of about 600 feet per minute to about 1000 feet per minute, orabout 675 feet per minute to 920 feet per minute. In one embodiment,each of the ambient and heated air supply units comprise a pressuresensor and/or an airflow sensor, this embodiment illustrated in FIG. 2,the sensors 281, 283 and 282, 284 disposed in the heated and ambientducts correspondingly. In this embodiment, the pressure and/or airflowsensors communicate data to the central control unit 270. In thisembodiment, the pressure and/or airflow rate sensors are part of afeedback loop which is discussed in more details elsewhere. The pressureand the airflow sensor can be a transducer, an analog or digital gauge,and may comprise a signal processing element(s). The first and/or thesecond air supply unit may include components for humidification,dehumidification, fragrance emitting elements, ionization elements, suchas tourmaline, and UV, IR or Visible radiation emitters. Any of the airsupply units may include a humidity sensor.

The air outlet is an aperture in the duct and may be located on any sideor part of the duct, such as a bottom part, an upper part or a sidepart. Preferably, the central air supply system has more than two airoutlets. The air outlets in the ambient air supply unit 232 and the airheated unit 222 may have different shapes, for example, a circular, arectangular, an oval, or an elliptical shape. These shape configurationsand their derivations are included in this invention. Preferably, theshape of the air outlets 223 and 233 is substantially circular asillustrated in FIG. 2 and FIG. 3. Preferably, the circular outlets havea diametric dimension in the range from about 2 cm to 14 cm, from about4 cm to 12 cm, and are preferably spaced apart about 5 m to 10 m, orabout 2 m to 4 m, about 1 m to 3 m, about 50 cm to 100 cm, while theinterior design and the placement of the users determine the placementof the outlets. The air outlet may comprise a sealing elastomeric ring.Preferably, each air outlet is in fluid communication with a Y-coupler(a mixing chamber) 420 via a motor-driven damper. In one embodiment,dampers may be spaced apart from the corresponding outlets and disposedwithin the Y-coupler, preferably within a rigid segment of theY-coupler, as schematically shown in FIG. 4. The ambient air supply unithas motor-driven damper and the heated air supply unit has motor-drivendamper, the different configurations of the dampers are shown in FIG. 3and indicated as 320, 330, 340 and 350. Different locations of thedampers are shown in FIG. 4.

In one embodiment, in the heated air supply unit 222, the outdoor airdrawn through the inlet air is passing through a heater assembly. Theairflow is generated by the variable speed fan system 240. The heaterassembly is interposed between the air inlet 201 and a variable speedfan system 240. The heater assembly comprises heater elements 235,controls for adjusting a current supply to heating elements 242 and aninsulating member (not shown). The heater location is aligned to permitpredetermined the air flow rate in the range of 0 cfm to 450 cfm to bemaintained within the duct. The heater elements 235 are preferably ofthe electrically resistive type and may contain ceramic elements. Theheater mounting support may comprise a highly resistant insulatingmaterial, which also forms a rigid support. The heater assembly may alsocontain protective devices, such as a thermal fuse and a thermal circuitbreaker to prevent the heater elements 235 from generating excessivetemperatures within the heated air supply unit 222. The heating isaccomplished by convection as the air passes across the heater elements,the heated airflow has a first temperature. The generated heated airflowis distributed through an airflow distribution system and associatedducting. The first temperature measured by a temperature sensor(s) 285disposed in the first duct is preferably in the range of about 60 C to100 C, from about 80 C to 100 C. The temperature may be controlled witha precision of, for example, ±12 C, ±10 C, ±7 C, preferably ±5 C withinthe predetermined temperature. For example, if the desired temperatureis set to 90 C, and the precision control is ±5 C, the temperaturevalues may be in a range between about 85 C to 95 C.

In another embodiment, the central air supply unit comprises onestructural unit, the unit comprising internal wall separating it to twoair pathways, the heated air pathway and the ambient air pathway.

In another embodiment, illustrated in FIG. 2 b, the central air supplyunit 200 comprises a temperature compensation unit (a preheater) 290located upstream from the air supply units. The preheater may preheatthe outdoor air drawn into the heated air supply unit 222 and/or theambient air supply unit 232, as shown is FIG. 2 b. The temperaturecompensation unit can preheat the outdoor air to the second temperature,e.g. to the temperature of the ambient air supply unit (the secondunit). The preheater 290 comprises heating elements 292 and currentcontrol 293. The preheater 290 may further comprise a temperature sensor291, a pressure sensor (not shown) and an air filter element 211. Thetemperature sensor 291 and other sensors that may be located in thepreheater provide input data to the central control unit, and thecurrent control 293 is regulated by the controller. Alternatively, thetemperature compensation unit 290 may comprise an evaporator systemand/or a condensate system. This embodiment may be useful in climateswith cold (or very hot) weather conditions or sharp fluctuations inoutdoor temperatures.

In general, the heated air supply unit and the ambient air supply unitare configured to generate similar maximum airflow rate. The heated airsupply unit (the first unit) generates an airflow at the higher range oftemperatures than the ambient air supply unit (the second unit). Thetemperature of the air emerging from the dryer depends on the ratiobetween the two airflow rates modulated by the dampers, the two airflowshaving different temperatures. The relative positions of the dampers donot affect the general airflow rate, airflow velocity and air pressurewithin the air supply units. The airflow delivery system to the multiplehandpieces is configured in combinations of paired dampers, each pair ofdampers connected to a Y-coupler. The lone segment of the Y-coupler isconnected to one handpiece via flexible tubing. Say it differently, eachfirst damper in an ambient air supply unit has a corresponding pairedsecond damper, preferably in an adjacent location, in the heated airsupply unit. Preferably, the ambient air supply unit and the heated airsupply unit include multiple paired dampers, such pairs are shownschematically in FIGS. 4 a, 4 b, and 4 c. Each pair of dampers deliversairflow to one individual dryer 120 through the corresponding Y-coupler420 and the flexible tubing 130. In one embodiment, the Y-coupler(mixing chamber) 420 can be spaced apart from the air outlets 223, 233.In this embodiment, the air outlets 223, 233 are in fluid communicationwith the Y-coupler 420 via flexible or rigid pipes 455, as shown in FIG.4 c. Each of the two paired dampers are controlled and operatedindependently, but in combination and in synchronization with eachother, providing an airflow at the temperature determined by anindividual user of a dryer. The operation of the dampers configured suchthat each damper in the pair provides similar maximum airflow rateentering the mixing chamber 420.

FIGS. 3 a, 3 b and 3 c depict exemplary alternative configurations of amotor-driven damper and its different positions. The motor-driven damperfacilitates sealing, partial opening and complete opening of the airoutlet with respect to the Y-coupler 420 positioned downstream, thusmodulating the airflow rate. Actuators 316 maneuver a motor-driven setof paired dampers to the suitable position by the controller accordingto the communication received from the central control system 270, basedon the inputs received by the central control unit from the dryer user.For example, a damper may comprise a cover member configured as asliding cover 340 or tilting (or pivotally connected) flap. Anotherexample of a damper comprises an axially rotating plate 320 as shown inFIG. 3 a. The actuating mechanism 316 which causes the movement ofdamper element(s) is shown schematically in FIGS. 3 a, 3 b and 3 c. Thedamper configurations may include a rotary valve, a cover member 340, acombination of a cover member 340 and a perforated plate 330, or a grid350 with rotating or tilting panels, operated by the actuating mechanism316. The perforations in the plate 330 may be of circular, rectangular,oval, or elliptical shape or the combination of thereof. Theseconfigurations and their derivations are included in this invention. Thetypical airflow rate when measured emerging from the dryer is in therange of about 10 liter per second to 50 liter per second, from about 10liter per second to 40 liter per second, from about 25 liter per secondto 45 liter per second, from about 30 liter per second to 50 liter persecond. The damper may comprise a circumferential seal and a filter. Thecomponents of a damper, the cover member, the plate, the grid panel arepreferably made from a suitable heat resisting plastic, although it isalso possible to utilize a suitable metal such as aluminum or sheetsteel. The damper and its components are replaceable and/or cleanable.

The examples of an operational relation between the position of dampersin ambient and heated ducts, and the corresponding temperatures andairflows are summarized in the Table 1. In general, a substantiallystable pressure in each duct is achieved by operating each of the fansat variable speeds corresponding to the command output from theprogrammable control system. In reference to Table 1, for example, whena damper in an ambient air supply unit is in a completely “open”position and a damper in a heated air damper is in a completely “closed”position, the airflow is at the maximum rate and will emerge from adryer at an ambient temperature designated “Cool” in the Table 1, forexample, at about 20 C. When a damper in an ambient air supply unit isin a completely “closed” position and a heated air damper is in acompletely “open” position, the airflow is at the maximum rate and willemerge from a dryer at hot temperature (“Hot”), for example, of about 70C. In this manner, as it is summarized in further detailed in Table 1,essentially any temperature ranging from the first temperature to thesecond temperature can be delivered to individual handpiece at differentflow rates. The air emerging from the Y-coupler 420 delivers an airflowto a dryer in the temperature range of about 15 C to 95 C, from about 20C to 85 C, or about 30 C to 75 C, the temperature measured at about 0.5cm to 5 cm from the hair or body surface. The drying temperature fromthe same hair dryer may be different because of the positioning distancebetween the body or hair and the dryer. In other words, although thetemperature of the air emerging from the hair dryer may be substantiallystable, the measured temperature increases as the distance between hairand hair dryer decreases and decreases as the distance from between hairand hair dryer increases.

In reference to FIGS. 4 a, 4 b and 4 c, a central air supply system 200may include a Y-coupler (mixing chamber). The incoming heated airflow atthe first temperature from the first outlet and the incoming ambientairflow at the second temperature from the second outlet are mixed inthe Y-coupler (mixing chamber) 420. In another embodiment, a conduit mayconnect the outlets 223, 233 to the Y-coupler 420. The conduit may beflexible pipe 455 and/or rigid pipe 456, the conduit may have a housing.The mixed airflow downstream of the Y-coupler is forced via the flexibletubing 130 and emerges from the handpiece 120. The flexible tubing 130may be extendable, e.g. it has adjustable length. It also may be modularand comprise adaptors, fittings, joints, ball joints, bearings, inparticular spherical bearings, rigid support, reinforcement elements,couplers and connectors 460, 490. Some of these elements may be used tochange a diameter of the tubing, or provide improved flexibility andmaneuverability, or alter the airflow rate. The diameter of the flexibletubing is in the range of about 2 cm to 8.0 cm, about 3.5 cm to 7.5 cm.It is advantageous to use quick release couplers 450, 480 to provideadditional convenience for the users. Quick release couplers allowquick, safe and convenient connection and disconnection of a dryer fromthe flexible tubing and/or the flexible tubing from the Y-coupler in thecase of desired re-location, maintenance etc. The diameter of the pipesmaybe different from the diameter of the Y-coupler. The diameter of thetubing at the exit from the Y-coupler may be different from the diameterat the entrance to the dryer, as it schematically shown in FIG. 4. Theflexible tubing may comprise elements that function as additional airdampers, dust collectors and ionizers. The flexible tubing can bemechanically supported, for example it can be mounted on a track. In oneembodiment, the flexible tubing may be supported by a system ofsuspended mechanical support (not shown). In another embodiment, theflexible tubing may be supported or stored when not in use on a mountdisposed on a floor, a wall, a table or a chair. The flexible tubing mayextend from a ceiling, a wall, a floor or other central or othersuitable remote location. The flexible tubing shape may be rectangulartubular or round tubular. The tubing has an adjustable length and thelength may be extended due to tubing material properties, telescopicstructure, coiled structure, flexible joints, or combination of thereof.The tubing is typically made of plastic used in similar air movementapplications and other light-weight applications. Typically the flexibletubing is made from heat resisting plastic, reinforced plastic such asPVC and its derivatives, plastic such as polyethylene, polyurethane,nylon, neoprene; resins, thermoplastic rubbers, silicon or theircombination. The tubing can also be made of metal sheathing, metalcoated fiberglass and corrugated stainless steel. It is desirable toutilize tubing material that is resistant to heat, resistant to heatfluctuations, abuse resistant, durable, can withstand elevated pressuresand airflow in the range of 2 bars. The flexible tubing can include heatinsulating sheath, acoustic insulating layer and decorative layer. Theflexible tubing can be colored, transparent, painted, anodized orotherwise configured to match various interior decor. In one preferredembodiment, the flexible tubing may comprise an electrical wiring, orwire harness, or electrical cable system to provide communicationbetween a dryer and a control system. In another preferred embodimentthe communication between the dryer and the control system is wireless.

The schematic depiction of a dryer (handpiece) is shown in FIG. 1 andFIG. 4. The typical handpiece is configured to connect to a flexibletubing and comprises a housing barrel which is preferably partiallycylindrical and partially tapered cylindrical. Any number of barrelshapes or combinations thereof, such as wholly cylindrical, rectangular,elliptical, etc., would also accomplish the barrel function of confiningand directing the air flow from the tubing while presenting very low airflow restrictions; these configurations and their derivations areincluded in this invention. The dryer has a gripping handle which may becollapsible or/and adjustable. The dryer may be adapted for suspension.The dryer may include any other typical removable accessories necessaryto perform a function of drying hair, hair styling or drying other bodyparts. The dryer unit can be portable or stationary and mounted on astand or a table. The user individually controls the air temperature andthe airflow level delivered to the dryer, as shown in a schematicdiagram in FIG. 5. The command input from the dryer is received by thecentral control system wirelessly or via an electrical conduit. Thedryer comprises user-controlled switches to select the desiredtemperature of airflow and the level of the airflow. The central controlis programmed with an algorithm, the algorithm comprises a safetyfunction which can cause an override of any of the input signals fromthe handpieces. A purpose of the safety function is to ensure that whenan airflow rate in the duct is very low and, for example, reaches thepredetermined value of about 5 cfm, the control system causesdisconnection of the current to the heating elements by setting thecurrent supply of the heating elements to zero. In other words, thesafety function overrides the inputs of the handpieces that may commanddelivery of heated air at that time. Another example of a safetyfunction in the algorithm, is when the temperature of the airflow in theduct exceeds a predetermined temperature of about 105 C it causesdisconnection of the current to the heating elements. The block diagramsin FIGS. 5a and 5b schematically depict these workflows. The handpieceswitches may have a configuration of a rocker button switch, a dialswitch, a rotary switch, a knob, a sliding know or a push on knob. Forexample, the user of the dryer can select different airflow rates, e.g.OFF, LOW, HIGH and different temperature settings, such as COOL, MEDIUM,HOT. There may be more selections of the airflow rates and thetemperatures settings. The dryer controls are shown by way of an exampleas a rotary dial in FIG. 5 a. The handpiece may comprise a timer, anairflow temperature sensor, an airflow rate sensor. In anotherembodiment, the dryer may comprise a heat sensor for a determination ofa hair or body part temperature. The sensor preferably is an Infra-redheat sensor and may communicate the data to the central control system.

In general, the main functions of the control system in each of the airsupply units are an electronic pressure regulator function and athermostatic function. In general, multiple dryer users commands arecommunicated to the central control system, as a result, the controllersends the signal that effects an actuation of the dampers, the positionof the dampers determines the desired temperature and the rate of theairflow delivered to each of the dryers. However, the overallpressure/airflow rate in each of the ducts has to be stable and has tobe maintained on a level that supply the total “demand”, e.g. the airflowing out through all the outlets in the duct. In one preferredembodiment, the pressure stability and the pressure supply are achievedby utilizing the pressure sensors/airflow sensors in the feedback loop.In this embodiment, the pressure/airflow sensors are disposed in eachduct, the sensors in communication with the central control system, asillustrated in the block diagram in FIG. 5 b. The central system definesa certain pressure value that has to be maintain in each of the airsupply units, schematically indicated by a circle that has a “setpoint”. The preprogrammed algorithm analyzes the feedback signals fromthe pressure/airflow sensor, and then provides an air pressure controlby communicating with the motor controls of the variable speed fan. Someof the logical functionality and interconnectivity of the control systemis shown in FIG. 5 b. The pressure and the temperature safetyfunctionality is also schematically shown in FIG. 5 b. The controlsystem in the heated air supply unit receives an input from thetemperature sensor and, based on the algorithm, generate command outputwhich is communicated to the heating elements as shown in FIG. 5 b. Ingeneral, the central control and/or the controller system maycommunicate with the pressure/airflow sensors, the dryers, the fan motorcontrols, the temperature sensors in a heated unit, the temperaturesensors in an optional preheater, and the actuators of the motor-drivendampers. The control system and/or the controller may also communicatewith an outdoor temperature sensor, a room (indoor) temperature sensor,a humidity sensor, an evaporator sensor or a safety device.

In another preferred embodiment, if further cost reduction or systemsimplification are desired, the central air delivery system may beconfigured to operate without a feedback from the pressure or airflowsensors in order to maintain the stable pressure at the desired leveland regulate the fan motor controls. In this embodiment, asschematically depicted in FIG. 5 c, the speed of the fan motors withineach of the air supply units operates at a predetermined speedmagnitude, the speed magnitude is adjusted to match the calculatedcombined airflow needed at any time, based on the input data receivedfrom all the handpieces. The central control is preprogrammed with atleast two lookup tables (arrays of values), and the exemplary valuesfrom these tables are presented in Table 2 and Table 3. One lookup tablecontains tabulated values of the airflow rate in a heated or ambientduct vs. the fan motor speed. Table 2 shows exemplary tabulated valuesof airflow rate (in units of cfm) vs. fan speed designation. Forexample, fan speed designated “1” can generate an airflow rate of about50 cfm. Another lookup table contains the total calculated airflow toall the Y-couplers given the positions of all the dampers in each duct.Table 3 shows exemplary tabulated values of total calculated to all theY-couplers vs. sum of all the dampers position for a system comprises offour dryers. In this example, the fully close damper position has anassigned value of “zero” and the fully open position damper position hasan assigned value of “one”. For example, if one damper is 50% open, ithas an assigned value of “0.5”, and if a second damper is 25% open, ithas an assigned value of 0.25. In this case the total sum of the twodamper positions has an assigned value of “0.75”. If, for example, in afully open damper position the airflow is 50 cfm, the correspondingrequired airflow for this sum of the damper position is 37.5 cfm. Everytime that a user adjusts the airflow level-selecting switch on thehandpiece, the algorithm adds together all the values of the totalcalculated airflow required in each of the ducts, the calculation basedon the input received according to the settings on all of the individualhandpieces. The central control unit using the algorithm and the lookuptables to find the motor speed value that corresponds to the totalcalculated airflow, and actuates the motor controls accordingly. Theprocess of accessing the lookup tables, is repeated for each of airsupply units, the hot air supply unit and the ambient air supply unit,every time the change is needed.

The components and procedures described above provide examples ofelements recited in the claims. They also provide examples of how aperson of ordinary skill in the art can make and use the claimedinvention. They are described here to provide enablement and best modewithout imposing limitations that are not recited in the claims. In someinstances in the above description, a term is followed by a similar termor alternative term enclosed in parentheses.

The following examples are provided to illustrate the invention, but arenot intended to limit the scope thereof. All parts and percentages areby weight unless otherwise indicated.

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable such as, for example,temperature, pressure, time and the like is, for example, from 1 to 90,preferably from 20 to 80, more preferably from 30 to 70, it is intendedthat values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. areexpressly enumerated in this specification. For values which are lessthan one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 asappropriate. These are only examples of what is specifically intendedand all possible combinations of numerical values between the lowestvalue and the highest value enumerated are to be considered to beexpressly stated in this application in a similar manner. As can beseen, the teaching of amounts expressed as “parts by weight” herein alsocontemplates the same ranges expressed in terms of percent by weight.Thus, an expression in the Detailed Description of the Invention of arange in terms of at “‘x’ parts by weight of the resulting polymericblend composition” also contemplates a teaching of ranges of samerecited amount of “x” in percent by weight of the resulting polymericblend composition.”

Unless otherwise stated, all ranges include both endpoints and allnumbers between the endpoints. The use of “about” or “approximately” inconnection with a range applies to both ends of the range. Thus, “about20 to 30” is intended to cover “about 20 to about 30”, inclusive of atleast the specified endpoints.

The disclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes. The term “consisting essentially of” to describe a combinationshall include the elements, ingredients, components or steps identified,and such other elements ingredients, components or steps that do notmaterially affect the basic and novel characteristics of thecombination. The use of the terms “comprising” or “including” todescribe combinations of elements, ingredients, components or stepsherein also contemplates embodiments that consist essentially of theelements, ingredients, components or steps. By use of the term “may”herein, it is intended that any described attributes that “may” beincluded are optional.

Plural elements, ingredients, components or steps can be provided by asingle integrated element, ingredient, component or step. Alternatively,a single integrated element, ingredient, component or step might bedivided into separate plural elements, ingredients, components or steps.The disclosure of “a” or “one” to describe an element, ingredient,component or step is not intended to foreclose additional elements,ingredients, components or steps.

It is understood that the above description is intended to beillustrative and not restrictive. Many embodiments as well as manyapplications besides the examples provided will be apparent to those ofskill in the art upon reading the above description. The scope of theinvention should, therefore, be determined not with reference to theabove description, but should instead be determined with reference tothe appended claims, along with the full scope of equivalents to whichsuch claims are entitled. The disclosures of all articles andreferences, including patent applications and publications, areincorporated by reference for all purposes. The omission in thefollowing claims of any aspect of subject matter that is disclosedherein is not a disclaimer of such subject matter, nor should it beregarded that the inventors did not consider such subject matter to bepart of the disclosed inventive subject matter.

TABLE 1 Position of a damper Airflow rate and Position of a Temperaturedamper in Position of a Airflow conditioned air damper in RateTemperature unit ambient air unit High Hot 1 (completely 0 (completelyopen) closed) High Medium ½ ½ High Cool 0 1 Low Hot ½ 0 Low Medium ¼ ¼Low Cool 0 ½ No — 0 0 Flow

TABLE 2 FAN MOTOR SPEED IN A HEATED OR AN AMBIENT DUCT AIR FLOW (cfm) 150 ± 8 2 100 ± 15 3 150 ± 23 4 200 ± 30

TABLE 3 TOTAL SUM OF POSITIONS OF DAMPERS IN A HEATED OR AN AMBIENT DUCT(VALUE 0.0 ASSIGNED TO CLOSED AIRFLOW RATE IN A POSITION, VALUE 1.0ASSIGNED TO HEATED OR AN FULLY OPEN POSITION) AMBIENT DUCT (cfm) 0 0-100.25 25 0.5 35 0.75 40 1.0 50 1.25 63 1.50 75 1.75 88 2.0 100 2.25 1132.50 125 2.75 138 3.0 150 3.25 163 3.50 175 3.75 188 4.0 200

1. A hair drying system comprising: a first duct configured to conduct afirst airflow that is at a first temperature; a second duct configuredto conduct a second airflow that is at a second temperature lower thanthe first temperature; first outlets that are spaced apart along thefirst duct ; second outlets that are spaced apart along the second ductand equal in number to first outlets; dryer handpieces equal in numberto the first outlets; Y-couplers, each Y-coupler including: a firstconduit connected to a respective one of the first outlets, a secondconduit connected to a respective one of the second outlets, and a thirdconduit connected to a respective one of the dryer handpieces, for thecoupler to combine a portion of the first airflow with a portion of thesecond airflow to yield a third airflow exiting the respectivehandpiece; first dampers, each first damper configured to control thefirst portion of the first airflow; second dampers, each second damperconfigured to control the second portion of the second airflow; and aprogrammable central control system configured to: control pressure ofthe first airflow, control pressure of the second airflow, control thefirst temperature; and for each handpiece, control the first damper andthe second damper that are associated with the respective handpiece tocontrol temperature of the third airflow exiting the handpiece.
 2. Thesystem of claim 1, wherein each first damper is located in a respectiveone of the first outlets, and each second damper is located in arespective one of the second outlets.
 3. The system of claim 1, furthercomprising: a first fan configured to generate the first airflow andcontrolled by the central control system; a second fan configured togenerate the second airflow and controlled by the central controlsystem.
 4. The system of claim 1, further comprising: temperaturesensors, each temperature sensor configured to measure temperature at arespective one of the air supply units, and wherein the control systemis configured to control temperature at the respective handpiece basedon the temperature measured for the respective one of the air supplyunits,
 5. The system of claim 1, further comprising: pressure or airflowsensors, each pressure or airflow sensor configured to measure apressure or an airflow rate at a respective one of the air supply units,and wherein the central control system is configured to control airflowor pressure at respective air supply units based on a feedback signalfrom the pressure or the airflow sensors by controlling fan motor speed.6. The system of claim 1, further comprising: a preheater locatedupstream from the first and second air supply units and configuredpreheat the first and second airflows to the second temperature; and afirst heater located downstream from the preheater and configured toheat the first airflow to the first temperature.
 7. The system of claim1, wherein the central control system includes: a controller; and foreach dryer handpiece: a first motor, controlled by the controller andcoupled to the corresponding first damper, to enable the controller tocontrol the corresponding first damper;